Atomic force microscopy has been used to study the surface properties of model
spray dried powders. Phase imaging, nanoindentation and force modulation
microscopy have differentiated between the different surface material properties
of the particles, revealing a regular dispersion of soft, oil rich areas distributed
across the particles’ surface. Humidity and temperature cycling effects on the
caking behavior of the particles have also been investigated, with significant
morphology changes and onset of caking found to occur within relatively short
periods of time.